South Korea extended its trade surplus streak to 55 months in August on the back of a turnaround in exports for the first time in 20 months, customs data showed Tuesday.

The country's trade surplus came to $5.1 billion last month, down from a record $7.6 billion in the previous month, according to the data from the Korea Customs Service.

The figure also marked a 17.8 percent on-year rise from $4.3 billion tallied in the same month a year earlier, continuing its bullish run for 55 months in a row since February 2012.

The parade of monthly trade surpluses is led by a downward trend in exports and imports that has lasted for nearly two years, although the latest figures posted a rebound thanks to one-off factors, including increased working days.

South Korea's exports rose 2.6 percent to $40.1 billion in August from a year ago to snap a 19-consecutive-month losing streak that started in January 2015.

At the same time, imports also turned around to edge up 0.7 percent to $35 billion last month, marking the first on-year growth in 23 months.

For the first 10 days of this month, however, exports retreated 3.6 percent on-year, dragged down by sluggish overseas demand for semiconductors and automobiles.

Experts expected outbound shipments for September to return to negative terrain due to still-low oil prices and a recent maritime logistics disruption stemming from the troubled Hanjin Shipping Co. (Yonhap)